Personal Computer Definition: The first general-purpose, cost-effective personal computer created by IBM was called the IBM PC or means "personal computer" . It is a microprocessor technology that has been any small, relatively inexpensive computer designed to be used by one person, at home or in an office. It is often simply called a Personal Computer (PC). The example of Personal Computer or PC are microcomputer, desktop computer, laptop computer, tablet. In all these computer manufacturers to put an entire CPU on one chip.

The successful general purpose mechanical computers were developed. In 1930, mechanical calculations were built for automatic addition, subtraction, multiplication & division. A calculator is not a programmable device. The different eras of the Evolution of Digital Computers are listed below:

What is Computer Bus: The electrically conducting path along which data is transmitted inside any digital electronic device. A Computer bus consists of a set of parallel conductors, which may be conventional wires, copper tracks on a PRINTED CIRCUIT BOARD, or microscopic aluminum trails on the surface of a silicon chip. Each wire carries just one bit, so the number of wires determines the largest data WORD the bus can transmit: a bus with eight wires can carry only 8-bit data words, and hence defines the device as an 8-bit device.

A computer bus normally has a single word memory circuit called a LATCH attached to either end, which briefly stores the word being transmitted and ensures that each bit has settled to its intended state before its value is transmitted.

The Industry Standard Architecture or ISA (Pronounced as separate letters or as eye-sa) bus began as part of IBM's revolutionary PC/XT and PC/AT released in 1981. However, it was officially recognized as "ISA" in 1987 when the IEEE (Institute of Electrical and Electronics Engineers) formally documented standards governing its 16-bit implementation. AT version of the bus is called the AT bus and became a de facto industry standard.

A Laptop computer(also calledportablecomputerornotebook computerin English) (Other terms, such as ultrabook or netbook, refer to specific types of laptop) is designed with portability in mind. It was developed in the late 1980s. It is briefcase style with a foldout screen with a clamshell form factor, suitable for mobile use and with a miniature keyboard. It is small enough to use in your lap. The laptop is battery or AC-powered personal computer that should be charged via a plug and socket, and when it runs out of power, it must be recharged regularly.

Definition: A supercomputer is the fastest computer in the world that can process a significant amount of data very quickly. The computing Performance of a "supercomputer" is measured very high as compared to a general purpose computer. The computing Performance of a supercomputer is measured in FLOPS (that is floating-point operations per second) instead of MIPS. The supercomputer consists of tens of thousands of processors which can perform billions and trillions of calculations per second, or you can say that supercomputers can deliver up to nearly a hundred quadrillions of FLOPS.

Definition: A minicomputer is also known as mini. It is a class of small computers that was introduced into the world in the mid-1960s. A minicomputer is a computer which has all the features of a large size computer, but its size is smaller than those. A minicomputer lies between the mainframe and the microcomputer because its size is smaller than the former one and larger than the latter one. A minicomputer is also called as a mid-range computer. Minicomputers are mainly multi-users systems where more than one user can work simultaneously. Mini computer examples: IBM’s AS/400e, Honeywell200, TI-990

The Processor Cache is memory that store data (code, commands etc.). it is used with the processor to facilitate the access of data from the system's main memory or RAM. Processor Cache reduces the average time to access memory. The processor cache typically consists of two levels, which are the L1 cache and the L2 cache.

Arithmetic Logic Unit (ALU): A subunit within a computer's central processing unit. ALU alu full form is Arithmetic Logic Unit, takes the data from Memory registers; ALU contains the logical circuit to perform mathematical operations like subtraction, addition, multiplication, division, logical operations and logical shifts on the values held in the processors registers or its accumulator.

The floppy disk drive also known asfloppy or FDD is the primary removable storage medium for a personal computer. The FDD, once called a mini disk, is the primary medium for getting voluminous information into and out of a micro computer system. If you have two FDDs of different storage capacities, A: In DOS and Windows the identifier used for the first floppy disk drive; the second floppy disk is designated as drive B:.